Method of developing wells



Feb. 6, 1940.

G. A. ZEIDLER, JR

METHOD OF DEVELOPING WELLS Filed Oct. 22, 1937 INVENTOR jwfl/ 1- Ze /0 y Patented Feb. 6, 1940 UNITED STATES PATENT OFFICE METHOD OF DEvELoPmd wELLs Gustav A. Zeidler, Jr., Medford Station, N. Y. Application October 22, 1937, Serial No. {male 1 Claim. c1. 166-21) The present invention relates to well drilling, and more particularly to an improved method of and means for finishing and developing wells using well screens or well strainers in sand or gravel.

When sinking wells for the purpose of obtaining or liquid bearing sand or gravel stratum. A

well screen or well strainer of any suitable design or type is then caused to be exposed to the water or liquid bearing sand or gravel below the pipe or well casing by means of driving, bailing, jetting, pull-back or other suitable methods and is attached to the well pipe or casing by means of pipe threads, welds, rivets, packers or other suitable joints or seals. The bottom of the well screen or strainer is plugged by any suitable device or method which will prevent infiltration of granular particles from the liquid bearing formation into the well.

In accordance with the present invention, the amount of water or other liquids which can be withdrawn from a well of a given depth and dimension is increased through the forming of a, natural gravel pack around the well screen or well strainer when in position in the well. This I invention accordingly contemplates the provision of a method of-and means for building or creating such a natural gravel pack around the well screen or well strainer to an extent sufiicient to increase the proportion of void spaces to solidmaterial in the granular structure surrounding the well screen or-well strainer, the greatest proportion of interstitial spaces to -solid material bein found in the area immediately surrounding the wellscreen, this proportion being gradually de-, creased outward from the well screen to the outer edge of the development area; In this manner more space is provided to be occupied by the water or liquid, larger screen openings can be used, and

I II.

paratus which may be used\when practising the invention, and Fig. 2 diagrammatically illustrates the four-way value shown at [4 in Figure 1. p

In the drawing there is shown a well casing I0 comprising at its lower end a screen I I. The well casing is connected by means of member l2 to a pipe 13 leading from the casing to a four-way valve 14, thatis, a valve connected to the four pipes .l3, l5, l6 and 19 by which the adjacent pairs of pipes may be made to communicate. This valve may be of any known typesuch as a ,conventional butterfly or four-way valve, shown schematically in Figure 2. When the lever 2| of the valve in the position shown, the valve vane 24 establishes communication between pipes I3 and IS on the one hand, and pipes l6 and I9 on the other hand. I When the handle 2i is rotated to the left, the valve vane 24 will assume the position indicated in dotted lines and communication is established between pipes 19 and 15 on the one hand, and pipes l6 and'l3 on the other hand. The valve [4 is interposed between the two vertical pipes l5 and I6 of a pipe system which comprises, as a means for causing a flow of water therethrough, a centrifugal or rotary pump H which is driven by means of a suitable 7 driving mechanism such as an internal combustion engine or an electric motor, shown schematically at 8, The valve it also establishes communication, by means of the vertical pipe portion is, with a reservoir or tank 2Q which is provided with discharge means such as a valve shown at 22.

In the practice of the present invention, the well casing it is sunk a suitable distance in the liquid-bearing stratum 9. The well screen H is set in proper position in said liquid-bearing stratum, either subsequent to the driving of the, well casing, or the screen may be formed integral with the casing and lowered simultaneously therewith. The liquid, such as water, for exam- 4 ple, is then pumped from the liquid-bearing stratum by means of the pump H. the valve Hi being set in a position to conduct the water upward through pipe l3, downward through pipe 15, through the pump I1, upward through pipe l6 and into the tank 20. After a suitable head'of 7 water has been formed in the tank 20, the valve lever 2| is rotated to the left to close the communication between conduits l6 and I9 andjestablish communication between conduits l9 and l5 on the one hand and I6 andl3 on the other hand. Clearly in this manner, the flow of water in the pipes l3 and I9 is reversed, the water being flo forced down under pressure by the pump II which is now used as a force pump, through pipe l3 and well casing in into the water-bearing stratum 9. The impact of the water with the constituents of the water-bearing stratum 9 results in a considerable turbulence and agitation of these constituents, whereby the finer portions deposited at the bottom of the settling tank 20..

The gravel and other mass of the constituents of the water-bearing stratum which are too coarse alternate cycles of pumping water into and from to pass through the openings of the screen will, as the fine particles are withdrawn with the pumped water, arrange themselves around the 'walls of the screen, thus increasing the proportion of cavities of the water-bearing stratum. By rotating lever 2|, the water of the settling tank will again be caused to fiow through pipes l9, l5, pump I'l, pipes I6 and I3, well casing [0, into the water-bearing stratum in a manner to temporarily increase the proportion of fine material to coarse material in the zone of the waterbearing stratum which surrounds the screen II. In this manner, by repeatedly alternating the functions of pumping from and into the well by means of changing the position of lever 2| the fine material will be-eliminated from the liquidbearing formation surrounding the well screen or well strainer, thus causing the coarse sand or gravel particles in the liquid-bearing formation to form around the well screen and in this man ner increase the capacity and life of the well.

Numerous modifications of the present invention will readily suggest themselves to those skilled in the art. For example, where the liquid-bearing formation does not contain in its natural condition sufiicient gravel or coarse constituents, such gravel or constituents may be introduced into said formation by conveying the same through suitable means to the bottom of the well. a

A typical illustration of the invention as applied to the drilling of a new well may be found in the sinking of so-called fire wells. This type of well is characterized by the fact that from its very nature and purpose, its use is contingent upon the occurrence of a fire, and if used at all, such a well will be employed only at infrequent time intervals. However, a well of this type, while it will generally be a relatively shallow'well, must be capable to yield, at any time, a considerable amount of water. The present invention, therefore, represents a considerably improved and valuable meth- 0d of and means for developing and/or conditioning such wells.

The followingis illustrative of the invenfion when applied to a well which, although in operation, has decreased in yield to a fraction of the original yield. Among the causes of such well deterioration are the presence of free iron or other metals whichare corroded away from the well casing or screen and redeposited in the water bearing stratum surrounding the screen, thus forming impervious coatings. Other common causes of well deterioration are the infiltration of fine particles of sand and/or silt into the region adjacent to the well screen in a manner such as to clog the perforations thereof; further, the deposition of the solid products of electrolytic corrosion of the well casing or well screen, as well as the deposition of free lime or other solid. substances. in the form of incrustations, around or. upon the. well screen. In accordance with the present invention, these obstructions are removed by the the well, as described, whereby the. coatings or deposits are broken up into fragments of which the smaller particles are removed, and the coarse constituents are arranged around and about the well screen in the manner described. In many instances, where theproportion of the incrustations or other deposits is found to be high, it has been found advantageous, in accordance with-this invention, to introduce into the well water a material which will react with I the incrusting or corrosive constituents thereof to form a precipitate which will be more readily removed. Such materials are sodium carbonate, or sodium phosphate, in proportions of ,between about 0.5% to 8% or more by weight; finely ground fiake'd graphite may be used to restore the supply of water to wells whose water is used primarily for purposes other than human or animal consumpticles, forcing said liquid down into the liquid-.

bearing stratum under pressure to cause it to impinge through the screened end thereof into the liquid-bearing formation, whereby the finer particles of said formation are loosened and caused to settle in the vicinity of said well screen, reversing the flow of liquid in the well casing to withdraw another portion of the liquid together;

with the suspended particles, and repeating this operative cycle until the fine particles of the formation surrounding the screen section of the well casing have been removed to the desired extent. GUSTAV A. ZEIDLER, Jr. 

